light speed and time

[THX1138]

I have been forever fascinated by the idea that if a person was to travel at light speed that time slows down and if one were to continue at that rate of speed for one year before turning around and coming back to earth something like ? Fifty thousand years would have gone by / earth time.
I cannot seem to grasp any inkling of how that is possible no matter what I have read on the subject, maybe I’m just not intelligent enough to fathom the idea ? But it’s just simply over my head how this could be.
Can anyone possibly offer a somewhat simplified reason / example of this as I would love to understand how that could be possible even a tiny bit.

[harry]

G'day

Time cannot change.

It cannot go faster or slower.

But! The relative time is another issue which involves the communication.

Because we communicate by EMR at the speed of C, the communication of that can be affected by distance or by a change in the Inertia frame.

[rstevenson]

In case Harry's answer didn't cause immediate illumination, you might want to try this Wikipedia article, as a starting point. ...
http://en.wikipedia.org/wiki/Time_dilation

Rob

[Chris Peterson]

I have been forever fascinated by the idea that if a person was to travel at light speed that time slows down and if one were to continue at that rate of speed for one year before turning around and coming back to earth something like ? Fifty thousand years would have gone by / earth time.
I cannot seem to grasp any inkling of how that is possible no matter what I have read on the subject, maybe I’m just not intelligent enough to fathom the idea ? But it’s just simply over my head how this could be.
Can anyone possibly offer a somewhat simplified reason / example of this as I would love to understand how that could be possible even a tiny bit.

I'll second the suggestion that you check the Wikipedia article. But here's the real problem: our common sense and instincts developed in response to our environment, and there are many things in nature outside that environment that behave in ways that defy our intuition. What's strange in those cases isn't nature, but our intuition- which never developed for things at the quantum level, for 4D spacetime, for speeds near c, and so forth.

It is possible, with both study and ongoing exposure to these ideas, for your intuition to adjust to match reality. But it may not do so for everybody, or for all subjects. At some point, you may simply need to accept that some things are true- because we can describe them rigorously and test those descriptions experimentally- but will seem unnatural nevertheless.

[Chris Peterson]

Because we communicate by EMR at the speed of C, the communication of that can be affected by distance or by a change in the Inertia frame.

The matter is more complex than communication. The example given was valid, and doesn't involve communication or EMR at all. If one person travels at high speed and returns, he will have experienced a shorter time interval than the people who stayed behind. That is easily determined on his return, and doesn't involve any sort of communication. Clearly, they each experienced different time lines. In a very real sense, you could say that time ran at different rates for each (although such an expression, using common language, doesn't exactly capture the nature of what happened as well as a bit of mathematical analysis).

[harry]

G'day Chris

I agree.

You are coming back to the Twin paradox.

Once again:

Why has the Twin that did the travelling have different Time?

Your logic previously answered this correctly.

Time cannot change. You can change the recorded time by altering the matter within the moving body.

[The Code]

Hi All

Just a post to stir things up a little,,,,

I Am matter, I Am also energy,,, My eyes and mind is also a mixture of both. My Brain uses electrons to send signals so I can work rest and play.... Question,, My body has already discovered The difference between Matter and Energy... Why do we have to learn it all over again? Everything I can see Or understand Is directly related to everything else. But what else are the things I can not see or understand related to? What created Gravity,,, Space time,,, Mass,,, And What Dictates the speed of light? And What other Energy can we not see yet?

Mark

[harry]

G'day Mark

We are only now understanding the subatomic particles that makes up Energy/Matter.

The LHC may give us a bit more.

[The Code]

G'day Mark

We are only now understanding the subatomic particles that makes up Energy/Matter.

The LHC may give us a bit more.

No harry,,,,

The LHC will just give us bucket load of new questions to answer.... We already have questions that can never be answered,,, you know that harry.... we just gona get a few more ,,,,, lmao....

Mark

[The Code]

Harry

The folk,, that made our prison.. Were very very clever....

Mark

[harry]

G'day

Mate do not loose you "A" from laughing.

LHC may give us more questions, but! we will learn more that we know little, although we know more than we knew last year.

[astrolabe]

Hello All,

I know that relative to us a body in motion will appear to have a slower clock. So is that all it is? A clock that only appears to run slower? IF that were true (a really big "IF"), what part would the curvature of spacetime play in having a clock "appear" to run slower? If that same body, even though in motion, was moving directly toward us would it's clock appear to be running faster?

[astrolabe]

Hello THX1138,

Out running those android cops was very cool on your part. Good thing the were over budget, eh? BTW how tall was that ladder anyway?

[Chris Peterson]

I know that relative to us a body in motion will appear to have a slower clock. So is that all it is? A clock that only appears to run slower? IF that were true (a really big "IF"),...

Why is that an IF at all? It is a fact- an experimental observation.

... what part would the curvature of spacetime play in having a clock "appear" to run slower? If that same body, even though in motion, was moving directly toward us would it's clock appear to be running faster?

It doesn't matter what direction the body is moving. If it is moving faster than the external observer, its clock is running slower (with respect to that outside observer). This has nothing to do with the curvature of space. A separate, but related effect causes two clocks at different gravitational potentials (which is, of course, associated with curved space) to run at different rates. The first effect is generally described by special relativity (as long as both the observer and moving body are in inertial frames); the second always requires general relativity for its analysis.

[astrolabe]

Hello Chris,

Thank you for clearing up a long-standing question I've been turning over for some time now. That being whether or not direction of motion plays a roll in the slower-clock issue. And that of spacetime curvature as well. Also, you are absolutely correct (if it was you) in saying that these types of things are definitely NOT intuitive! At least for me.

[The Code]

Hi,,, THX1138

I am also fascinated by the same thing,, some more info....

http://www.mathpages.com/rr/s6-06/6-06.htm

Mark